Abstract: Servo mechanism is the core component of electro-optic stabilized platform，and its low speed performance and stable precision are the key technical indicators. The satisfactory performance of electro-optic stabilized platform is always difficult to be achieved due to the nonlinear disturbance，which cannot be eliminated by linear close-loop method, such as PID control law. A control method based on the state augmented Kalman filter (SAKF) is proposed to suppress the torque disturbance. The numerous groups of experiments were conducted for method verification, which shows a well compensation for the torque disturbance and the significant improvements of low speed performance and stable precision by the SAKF-based control method. Key

Key words: electro-opticservosystem, Kalmanfilter, disturbancecompensation, feedforwordcontrol, lowspeedperformance, stabilizationaccuracy